Improvement in grate-bars



, UNITED STATES PATENT OFFICE.

JAMES MCDONALD, OF CINCINNATI, OHIO.

IMPROVEMENT IN GRATE-BARS.

Specification forming .part oi' Letters Patent No. 42,099, dated March29, 1864.

To all whom it may concern Be it known that I, JAMES 'MCDONALD, ot'Cincinnati, Hamilton county, Ohio, have invented a new and usefulImprovement in Furnace-Grate Bars and I do hereby declare the followingto be a full, clear, and exact description thereof, reference being hadtothe accompanying drawings, making part of this specication.

This invention is an improvement on the movable grate-bar forsteam-boiler furnaces, the same being adapted for more effective andvaried agitation than devices heretofore einployed for this purpose.

Figure l is a plan of a portion of a grate,

\ illustrating my invention. Fig. 2 is a longitudinaI section thereof'.Fig. 3 is an enlarged transverse section taken at different parts of thebars. j

A A represent, respectively, the front'and the back bearing-bars.

The grate-bars B terminate at their front ends iu handles C,whichprotrude through an opening, D, in the furnace-front, while theirrear ends are provided with hemispherical projections or balls E, whichoccupy corresponding sockets F in the iearl bearing-bar Af, so as toform universal joints.

When in place, the shoulders K K of each I claim herein as new and 'ofmy inventionv 1. Connecting the bars ot' a furnacegrate to the rearbearing by unversaljoints E F, which enable the bars to be agitated inthree several modes or directions, .as set forth.

2. The provision on a universal jointed gratebar of shoulders K K andfillet G, vin the described combination with the jog H in thebearing-bar, for retaining such grate-bars iirmly in position when atrest, as herein explained. t

In testimony ot' which inventionI hereunto set my hand.

JAMES MCDONALD.

Witnesses:

GEO. H. KNIGHT, J QNATHAN OREAGER.

